Canonical URL
A canonical URL is the version of a page you declare as the original when the same content is reachable at several addresses.
In detail
The rel=canonical tag consolidates signals onto one address, avoiding self-competition between duplicates such as parameter and trailing-slash variants.
A canonical pointing at the wrong page removes the page you actually wanted indexed.
Example
A guide whose canonical tag points at the section index will usually not be indexed on its own.
Why it matters
Wrong canonicals quietly delete pages from search results without any visible error.
Common mistakes
- Hardcoding one canonical across a template.
- Canonicalising a detail page to its category.
Related questions
Related guides
- The Complete SEO GuideGuide
A cornerstone guide to organic search: technical foundation, on-page work, content, internal linking, authority and measurement — in the order that pays off.
Related terms
- Indexability
Indexability is whether a page is eligible to be stored in a search engine's index and shown in results.
- Technical SEO
Technical SEO covers everything that determines whether search engines can reach, render, index and trust your pages.
- XML Sitemap
An XML sitemap is a file listing the URLs you want search engines to know about, used as a discovery source.
Related questions
- How can I improve my Google ranking?
Start by removing the reasons a page cannot rank at all: error responses, accidental noindex directives, wrong canonical URLs, pages no internal link points to.